Lee C S, Curtis D, McCarron M, Love C, Gray M, Bender W, Chovnick A
Genetics. 1987 May;116(1):55-66. doi: 10.1093/genetics/116.1.55.
The rosy locus in Drosophila melanogaster codes for the enzyme xanthine dehydrogenase (XDH). Previous studies defined a "control element" near the 5' end of the gene, where variant sites affected the amount of rosy mRNA and protein produced. We have determined the DNA sequence of this region from both genomic and cDNA clones, and from the ry+10 underproducer strain. This variant strain had many sequence differences, so that the site of the regulatory change could not be fixed. A mutagenesis was also undertaken to isolate new regulatory mutations. We induced 376 new mutations with 1-ethyl-1-nitrosourea (ENU) and screened them to isolate those that reduced the amount of XDH protein produced, but did not change the properties of the enzyme. Genetic mapping was used to find mutations located near the 5' end of the gene. DNA from each of seven mutants was cloned and sequenced through the 5' region. Mutant base changes were identified in all seven; they appear to affect splicing and translation of the rosy mRNA. In a related study (T. P. Keith et al. 1987), the genomic and cDNA sequences are extended through the 3' end of the gene; the combined sequences define the processing pattern of the rosy transcript and predict the amino acid sequence of XDH.
果蝇中的朱红基因座编码黄嘌呤脱氢酶（XDH）。先前的研究在该基因5'端附近定义了一个“控制元件”，其中的变异位点会影响朱红基因mRNA和产生的蛋白质的量。我们已经从基因组克隆、cDNA克隆以及ry +10低产生株中确定了该区域的DNA序列。这个变异株有许多序列差异，因此调控变化的位点无法确定。我们还进行了诱变以分离新的调控突变。我们用1-乙基-1-亚硝基脲（ENU）诱导了376个新突变，并对它们进行筛选以分离出那些减少XDH蛋白产生量但不改变酶性质的突变。利用遗传图谱来寻找位于该基因5'端附近的突变。七个突变体中每个突变体的DNA都被克隆，并对5'区域进行了测序。在所有七个突变体中都鉴定出了碱基变化；它们似乎影响了朱红基因mRNA的剪接和翻译。在一项相关研究（T.P.基思等人，1987年）中，基因组和cDNA序列延伸到了该基因的3'端；这些组合序列确定了朱红转录本的加工模式，并预测了XDH的氨基酸序列。
